What is I/I? Infiltration - water entering a sewer system and service connections from the ground through such means as, Inflow and Infiltration but not limited to, pipes, pipe joints, connections, manhole walls or manhole joints Inflow - The water discharged into a sewer system, including service connections, from such sources as, Monday, December 12, 2005 but not limited to; roof leaders; yard and area drains; foundation drains; cooling water discharges; drains Ohio EPA Northwest District Office from springs and swampy areas; manhole covers; cross connections from storm sewers; surface runoff; or drainage What is I/I? Who Needs I/I Credits? Every Combined Sewer Overflow (CSO) and Sanitary Sewer Overflow (SSO) community that does not have a Long Term Control Plan I/I = The total quantity of water from both approved by Ohio EPA or US EPA infiltration and inflow without distinguishing the source. Each WWTP that has reached its design hydraulic average daily flow or its biological treatment capacity I/I Removal Credits How I/I Removal Credit Works Brief History Antidegradation Rule (Ohio Administrative Code 3745-1-05) went into effect in 1998 which required any PTI projects that For every 1 gallon of sewage flow added to resulted in additional pollutants being discharged to waters of the sewer system, 3.33 gallons (peak flow) the state to go through the Antidegradation review. of inflow and infiltration need to be NWDO developed the I/I removal credit program to help removed through repairs and maintenance CSO communities avoid going through the antidegradation to the sewer system review for each sanitary sewer extension. 1 What needs to be submitted with a PTI How I/I Removal Credit Works What needs to be submitted with a PTI How I/I Removal Credit Works Application? Consulting engineers will need to obtain a letter To obtain credits with NWDO CSO from the CSO community indicating that the communities could do the following projects community will allocate I/I credits for the Manhole Rehabilitation proposed sewer extension and submit it to NWDO as part of the PTI submittal package. Install Chimney Seals Abandon and Remove Sewers with high I/I NWDO-DSW tracks the I/I credits on a Replace Damaged Sewer Mains spreadsheet for each community and includes a Sump pump removal special condition in the PTI related to I/I removal and flow credits Common Questions? Are I/I removal credits needed for a sewer extension that goes to the WWTP directly and is not upstream or downstream of a Questions??? CSO? - Yes, because the flow from the new sewer is taking up treatment capacity at the WWTP, however if WWTP has a Long Term Control Plan approved by Ohio EPA or US EPA then I/I removal credits are not needed 2.